Container sealing method



Oct. 19, 1965 H. RYCHIGER CONTAINER SEALING METHOD 2 Sheets-Sheet 1 Filed June 4, 196s FMEA FIG.

FIELZ Oct. 19, 1965 Filed June 4, 19615 H. RYCHIGER 2 Sheets-Sheet 2 FI G. E FI E. 7

i s [+3 5o 51 4 l 47 i r [+2 I 48 n 40 i 4o t f r 1 JI l ril/ 4 i FI E.. 8 TI EL 9 1 @Ik 41\1 4 l 42 f 48 l I to +8 I l l /f /fu/fyfm- United States Patent O 3,212,468 CONTAINER SEALING METHOD Hans Rychiger, Steffisburg, near Thun, Switzerland, assignor to Alupak A.G., Bern, Switzerland Filed June 4, 1963, Ser. No. 285,518 Claims priority, application Switzerland, June 5, 1962, 6,778/ 62 6 Claims. '(Cl. 113-121) This invention relates to a method for closing or sealing containers and in particular containers having a filling hole for .the commodity to be packed, the hole" having a rirn flange which can be covered by a closing material such as foil or film, preferably of a thin sheet material, such as light metal foil which may be saucer shaped or in `the form of a hollow shell. Such containers are frequently used for the preparation, transportation and display for sale of foodstuffs, e.g. rations ready for consumpti-on, cheesecake -or fruitcake `and the like, as well as presenting the food for eating. T-o eoonomise in packaging material, which would otherwise be large enough to envelope the whole container, the filling hole is frequently covered or sealed with a covering foil, e.g. of transparent synthetic material Ior light metal. Since several such containers are stacke-d one on top |of another especially during transportation ,and on display for sale, the covering foil must be anchored sufficiently firmly to the rim flange of the container to be able -to withstand a surface load of at least approximately 40 grs/cm.2 without being drawn out of its attachment to the rim flange. The use of an adhesive for attaching the cover or seal to the container 'flange would make the sealing procedure laborious, slow and expensive.

Tests have shown, that covering foils may be anchored more easily to the rim flange of the container, if they a-re not very th-in. Since the material in questi-on is intended to be expendable, the thinnest possible covering materials are the most suitable economically.

-Th-e main object of the present invention is to provide .a reliable closure of containers even with very thin covering foils, e.g. of less than 0.05 mm. thickness, without adhesive, the covering foil for this purpose initially being set down firmly on the flat inner area of the rim flange.

According to present invention, there is provided a method for closing or sealing .a filling orice of a container made of thin sheet material along a rim flange extending around the orifice by means of a covering foil which .is initially laid firmly on a flat inner area of the flange the outer area of which forms an upright surround for the inner ilange area, characterised in that the outer flange area is swaged over inwards towards the covering foil and is then, with the edge of `the foil between itself and the .inner flange area bent downwards together with the two latter .and upset along the bending line in the form of a groove or channel, whereupon the still downwardly directed outer edge of the flange is upset by the comp-ression of material against the part of the flange exhibiting the fold.

The container is made of thin sheet material, whereof the filling hole is closed off by a covering foil sealed along a rim flange extending around said hole, the edge of the covering foil being held fast between two flange areas which together with the edge of the foil exhibit a surr-ounding fold in the form of a groove or channel, its outer edge being upset by the compression or squeezing together of material.

In order that the invention may be more fully understood two embodiments of 4apparatus for cl-osing a container in accordance with the invention will n-ow be described by way of example, with reference to the accompanying drawings, in which:

FIGURE 1 shows a cross section through a container sealing apparatus;

3,212,468 Patented Oct. 19, 1965 ICC FIGURES 2 to 5 show parts of the sealing elements of the apparatus in four different stages of the sealing operation, and

FIGURES 6 to 9 'sh-ow parts of the sealing elements of another construction of apparatus in four stages of the sealing operation.

In the drawings lthe same references are used to designate the same parts.

Referring to the drawings, a cup-like round container 1 preferably made of thin aluminium sheet, has an upper circular aperture 2 surrounded by a projecting rim flange, having an outer annular area 3 bent upwards initially at right angles around the remaining part of the flange forming a flat inner rim area 3", on which is placed a plane cove-ring f-oil 5 made of transparent synthetic material for example or light metal of less than 0.05 mm. thickness for example, and fitting into t-he surround 3.

The container 1 ready for sealing, is moved over a table 6 on a carrying plate 7 of the sealing mechanism shown in FIGURE 1. By pedal actuation or motorised drive (not shown), a push-rod 9 or the like guided in the lower part 8 of the mechanism is raised to lift a plate 10 replace- :ably secured thereto. On the plate is disposed a co-axial thrust ring 11 urged to move axially with respect to the plate by compression springs 12 (FIGURE 2) so that its end face 113 engages against the underside of the flange area 3 simultaneously centring the container 1 by means of its inner tapered face 14. As the stroke of this axial movement progresses, the container 1 is lifted off the carrying plate 7 by the thrust rin-g 11 until the upper s-ide of the flange area 3" with the edge of a covering foil 5 resting thereon, engages .an annular edge 15 of an upper plate 16 which is repl-aceably secured co-axially to the lower plate 10 to a rod 18 axially guided in a sleeve 17 on the upper part 18 of the apparatus.

As the .axial st-roke progresses fur-ther against the weight of the plate V16 and the rod 19, the covering foil 5 is held fast on the flange area 3 and the upright flange area 3 is raised into the pat-h of at least two beading or llanging rollers 21 which are each rotatably mounted in a bracket 23 with their axes of r-ot-ation 22 extending radially of the plate 16, the two brackets being secured radially displaceably in corresponding radial slots 24 of a V-belt pulley 25 mounted co-.axially with the sleeve 17 in the upper part 18 of the apparatus, t-o allow adjustment to different container sizes. During the rotation of the pulley 25 driven by an electric motor 26 through a V-belt 27, th-e beading rollers 21 circle around the plate 16 in diametrical disposition relative to each other. The flange yarea 3", coming into contact with the revolving beading rollers 21, is inclined inwards (FIGURE 2) towards the covering foil S by the tapering peripheral faces 28 and 29 of said rollers.

As the stroke progresses further, the lower part of the flange .are-a 3 together with the edge lof the covering foil 5 and a part of the flange area 3, is bent over downwards, initially by the tapered faces 28 and 29 of the rollers 21 and subsequently, along the outer side of the thrust ring 11, by the end face 31 of the rollers roll-ing along the flange of the container, said end face extending radially beyond an annular projection 30 on the beading rollers 21, the edge of the covering foil thereby being clamped between the two flanges areas 3 and 3". The flange part 3' is set upright again in doing so, and extends Iapproximately up to the roller projection 30 (FIG- URE 3), which now comes into operation wit-h Aits taperingly undercut peripheral surface 32 along the bending line of Ithe container flange and partially presses the latter into an annular groove 33 Ibeneath the bending line on the thrust ring 11, and simultaneously upsetting the upper edge of the flange part 3 thereby forming a groove or channel fold 34 (FIGURE 4) extending circumferentially in the flange of the container. The plate 16 has now reached in top dead centre position, in which the upper end face 35 of the rod 19 bears against an axially adjustable abutment screw 36 (FIGURE 1).

Continued lift of the plate 10 now causes compression of the springs 12 .and thus merely the lifting of an upsetting ring 37 which surrounds the thrust ring 11 coaxially and is displaced upwards relative thereto and in doing so upsets the downwardly extending part 38 of the flan-ge rim (FIGURE with its upper end face 39 (FIG- U-RE 1) which is trough-shaped in section. By this compression of material, a very compact folded or creased joint is formed between the flange and the e-dge of the foil, the latter thereby being most satisfactorily anc-hored, Whilst the flange itself is reinforced and thereby strengthened against deformation.

After this final stage in the sealing sequence, the sealed c-ontainer is lowered lon to the carrying plate 7 and drawn out of the mechanism. Where the stroke is caused by means of an electric motor, a -switch-ing system may be employed which keeps the motor in operati-on for a single stroke and return str-oke, after it has been switched on manually.

The plates yand 16 and the aforesaid components therewith are exchangeable in order to allow containers of different size to be sealed by means of the said apparatus.

Sealing the container 1 with the covering foil 5 may be effected by means of press rams instead of the beading rollers 21. The two thrust rings 41 and 46 are retained wi-thout change the former being supported by spr-ings 42 on the machine bed 40. The upper thrust ring 46 is surrounded by a co-axial .annular press ram 43 for example, opposed axially by a counter ring 49 supported res-iliently on springs 48 4and the upsetting ring 47, which co-axially to each other and to the lower thrust ring 41 surround the ring 41, Ion which the upsetting ring 47 is rigidly secured. In this construction the two thrust rings 41 and 46 again press the edge of t-he covering foil 5 against the inner annular area 3 of the flange of the container, t-he counter-ring 49 suppor-ting the extreme edge of this annular area 3 from beneath. The upright annular area 3 of the flange of the container is now bent over inwards by the end-side taper face 44 of the d-ownwardly displaced annular press ram 43 (FIGURE 6) until the radial end face 45 of this ram strikes the counter-ring 49 face and axially displaces it against its resilient supporting spring 48. In ydoing so, the flange 3', 3 of the container is bent downwards as in FIGURE 7. By the continue-d downward displacement of the annular press ram 43, which on the inner side has an undercut shoulder 50, the groove-shaped fold 34 is formed in the flange of the container by said shoulder as in FIGURE 8. The plate surface 51 of the annular press ram 43 now strikes the upper thrust ring 46 and in its downward motion entrains the same and thus also the container 1 and the lower thrust ring 41. Consequently, the downwardly folded part of the flange of the container is upset by means of the upsetting ring .as in FIGURE 9. The ram 43 and 4the upper thrust ring are then raised and the sealed container may be withdrawn.

1. A method lof sealing a filling opening of a container made of thin sheet material and having a flange surrounding the opening and including an inner annular radially outwardly extending flange portion and an outer .annular flange portion projecting from the outer periphery of said inner flange portion substantially normal thereto, said method comprising the steps of placing a covering foil yover said opening and sai-d inner flange portion; swaging said outer flange portion inwardly t-owards said covering foil; bending said flange portions with a peripheral portion of said foil located therebetween downwardly; and deforming said three portions into an annular flange of zigzag cross .section while axially compressing the same.

2. A method of sealing a lling opening of a container made of thin sheet material and having a flange surrounding the lopening and including an inner annular radially outwardly extending flange portion and an outer annular flange portion substantially normal thereto, said method comprising the step-s of placing a covering foil over said opening and said inner tflange portion; swaging said outer flange portion inwardly towards said covering foil; bending said flange portions with 4a peripheral portion -of said foil located therebetween downwardly; ups-etting at least said inner flange portion and said peripheral portion of said foil into `an annular flange of substantially N-shaped cross section having an annular groove open at the top and an outer leg portion extending downwardly beyond the bottom of the groove; and compressing said outer leg portion and the outer `flange portion connected thereto in axial direction while pressing the free edge of said outer flange portion into said grooove.

3. A method of sealing a filling opening of a container made of thin sheet material and having a flange surrounding the opening and including an inner, flat, annular radially outwardly extending flange portion and an outer annular flange portion projecting from the outer periphery of said inner flange portion substantially normal thereto, said method comprising the steps of placing a flat cover foil over -said opening and said inner flange portion with the outer periphery of said foil engaging said outer flange portion; clamping said inner flange portion in the region of the inner periphery thereof against said foil; swaging said outer flange portion inwardly towards said covering foil; bending said flange portions with a peripheral portion of said foil located vtherebetween downwardly; upsetting at least said inner flange portion and said peripheral portion of said foil int-o an annular flange of sub- 1 stantially N-shaped cross section having an annular groove open at the top and an outer leg portion extending downwardly beyond the bottom of the groove; and compressing said outer leg portion and the outer flange portion connected thereto in axial direction while pressing the free .f edge of said outer Iflange portion into said groove.

4. A method as set forth in claim 1 wherein said swaging, deforming and compressing steps are effected during a ysingle stroke of the container against at least one working member circling along said flange.

5. A method as set forth in claim '1 wherein said swaging, deforming and compressing steps are effected during a single movement of two annular press members toward each other.

6. A method as set forth in claim 1 wherein said swaging, deforming and compressing steps are effected during a single movement of two annular press members toward each other, one engaging said inner flange portion and the other said outer flange portion.

References Cited by the Examiner UNITED STATES PATENTS 1,995,860 3/35 Mundy 113-30 2,104,224 l/38 Fisher 113-30 3,070,058 12/62 Boyer 113-121 3,073,480 l/63 Henchert 220-67 3,083,663 4/63 Stuchbery et al. 113-121 3,108,710 10/63 Lange et al. 220-67 CHARLES W. LANHAM, Primary Examiner. THERON E. CONDON, Examiner. 

1. A METHOD OF SEALING A FILLING OPENING OF A CONTAINER MADE OF THIN SHEET MATERIAL AND HAVING A FLANGE SURROUNDING THE OPENING AND INCLUDING AN INNER ANNULAR RADIALLY OUTWARDLY EXTENDING FLANGE PORTION AND AN OUTER ANNULAR FLANGE PORTION PROJECTING FROM THE OUTER PERIPHERY OF SAID INNER FLANGE PORTION SUBSTANTIALLY NORMAL THERETO, SAID METHOD COMPRISING THE STEPS OF PLACING A COVERING FOIL OVER SAID OPENING AND SAID INNER FLANGE PORTION; SWAGING SAID OUTER FLANGE PORTION INWARDLY TOWARDS SAID COVERIONG FOIL; BENDING SAID FLANGE PORTIONS WITH A PERIPHERAL 